Ligno JET Filter

Maximum system availability and efficiency

The Scheuch LIGNO jet filter is used especially for air-aggressive dusts, as special attributes are required here.

The jet filter is used to dedust pelletisers or their coolers due to the high moisture content in painted and insulated versions.

The filter bags are cleaned using compressed air pulses. The dust-laden crude gas enters the filter casing and is diverted upwards by a baffle plate. This process protects the filter bags from premature wear and allows pre-separation of coarse particles and contamination. The dust particles are retained on the surface of the filter medium and, in a subsequent step, are blown off the bags using compressed air. The separated dust falls into the dust-collecting trough, and the discharge screw conveys the separated material out of the filter continuously. The clean air leaves the system via the clean gas chamber of the filtration plant or, if required, can be fed back into the production hall as return air.

  • Clean gas outlet

  • Clean gas chamber with jet pipes and injectors

  • Compressed air tank

  • Crude gas chamber

  • Baffle plate

  • Dust-collecting trough with discharge screw and outlet

  • Crude gas inlet

  • Maintenance opening

  • Pressure relief


Efficient planning for winterproofing: optimum gas temperature due to strategic supplementary extraction design

When dedusting a pellet cooler, the cooler exhaust air temperature is around 60 °C.

The absolute humidity in the cooler air differs for each owner. The higher the moisture content (the maximum value is standardised) in the pellets, the more moist the extracted air. For example, customer A’s absolute moisture is 29 %, customer B’s is 36 %, customer C’s is 52 % and customer D’s is 64 %.

As the dew point is also lower if the absolute moisture is higher, the dew point is not reached sooner on cold bridges or areas that are not insulated. The organic substances contained in the exhaust air (formic acid, acetic acid) attack the galvanized surface and cause corrosion.

By adding exhaust air from supplementary extraction systems (e.g. HGV loading) decreases the temperature difference between the dew point and the gas temperature again. In summer, the temperature difference dip is less critical due to the high ambient temperatures but this can cause problems in winter. In order to avoid problems, the share of supplementary extraction systems should already be considered during planning so that the gas temperature remains 10 °C above the dew point even in winter. The jet filter ensures maximum system availability and efficiency